diff --git a/packages/gatsby-plugin-manifest/src/__tests__/gatsby-node.js b/packages/gatsby-plugin-manifest/src/__tests__/gatsby-node.js
index 7ae8021f9e184..718b5e5c9350e 100644
--- a/packages/gatsby-plugin-manifest/src/__tests__/gatsby-node.js
+++ b/packages/gatsby-plugin-manifest/src/__tests__/gatsby-node.js
@@ -10,6 +10,7 @@ jest.mock(`fs`, () => {
  * We mock sharp because it depends on fs implementation (which is mocked)
  * this causes test failures, so mock it to avoid
  */
+
 jest.mock(`sharp`, () => {
   let sharp = jest.fn(
     () =>
@@ -20,16 +21,31 @@ jest.mock(`sharp`, () => {
         toFile() {
           return Promise.resolve()
         }
+        metadata() {
+          return {
+            width: 128,
+            height: 128,
+          }
+        }
       }()
   )
   sharp.simd = jest.fn()
   sharp.concurrency = jest.fn()
+
   return sharp
 })
 
 const fs = require(`fs`)
 const path = require(`path`)
 const sharp = require(`sharp`)
+const reporter = {
+  activityTimer: jest.fn().mockImplementation(function() {
+    return {
+      start: jest.fn(),
+      end: jest.fn(),
+    }
+  }),
+}
 const { onPostBootstrap } = require(`../gatsby-node`)
 
 const manifestOptions = {
@@ -60,14 +76,17 @@ describe(`Test plugin manifest options`, () => {
   })
 
   it(`correctly works with default parameters`, async () => {
-    await onPostBootstrap([], {
-      name: `GatsbyJS`,
-      short_name: `GatsbyJS`,
-      start_url: `/`,
-      background_color: `#f7f0eb`,
-      theme_color: `#a2466c`,
-      display: `standalone`,
-    })
+    await onPostBootstrap(
+      { reporter },
+      {
+        name: `GatsbyJS`,
+        short_name: `GatsbyJS`,
+        start_url: `/`,
+        background_color: `#f7f0eb`,
+        theme_color: `#a2466c`,
+        display: `standalone`,
+      }
+    )
     const [filePath, contents] = fs.writeFileSync.mock.calls[0]
     expect(filePath).toEqual(path.join(`public`, `manifest.webmanifest`))
     expect(sharp).toHaveBeenCalledTimes(0)
@@ -80,46 +99,52 @@ describe(`Test plugin manifest options`, () => {
     const icon = `pretend/this/exists.png`
     const size = 48
 
-    await onPostBootstrap([], {
-      name: `GatsbyJS`,
-      short_name: `GatsbyJS`,
-      start_url: `/`,
-      background_color: `#f7f0eb`,
-      theme_color: `#a2466c`,
-      display: `standalone`,
-      icon,
-      icons: [
-        {
-          src: `icons/icon-48x48.png`,
-          sizes: `${size}x${size}`,
-          type: `image/png`,
-        },
-      ],
-    })
+    await onPostBootstrap(
+      { reporter },
+      {
+        name: `GatsbyJS`,
+        short_name: `GatsbyJS`,
+        start_url: `/`,
+        background_color: `#f7f0eb`,
+        theme_color: `#a2466c`,
+        display: `standalone`,
+        icon,
+        icons: [
+          {
+            src: `icons/icon-48x48.png`,
+            sizes: `${size}x${size}`,
+            type: `image/png`,
+          },
+        ],
+      }
+    )
 
     expect(sharp).toHaveBeenCalledWith(icon, { density: size })
-    expect(sharp).toHaveBeenCalledTimes(1)
+    expect(sharp).toHaveBeenCalledTimes(2)
   })
 
   it(`fails on non existing icon`, async () => {
     fs.statSync.mockReturnValueOnce({ isFile: () => false })
 
-    return onPostBootstrap([], {
-      name: `GatsbyJS`,
-      short_name: `GatsbyJS`,
-      start_url: `/`,
-      background_color: `#f7f0eb`,
-      theme_color: `#a2466c`,
-      display: `standalone`,
-      icon: `non/existing/path`,
-      icons: [
-        {
-          src: `icons/icon-48x48.png`,
-          sizes: `48x48`,
-          type: `image/png`,
-        },
-      ],
-    }).catch(err => {
+    return onPostBootstrap(
+      { reporter },
+      {
+        name: `GatsbyJS`,
+        short_name: `GatsbyJS`,
+        start_url: `/`,
+        background_color: `#f7f0eb`,
+        theme_color: `#a2466c`,
+        display: `standalone`,
+        icon: `non/existing/path`,
+        icons: [
+          {
+            src: `icons/icon-48x48.png`,
+            sizes: `48x48`,
+            type: `image/png`,
+          },
+        ],
+      }
+    ).catch(err => {
       expect(sharp).toHaveBeenCalledTimes(0)
       expect(err).toBe(
         `icon (non/existing/path) does not exist as defined in gatsby-config.js. Make sure the file exists relative to the root of the site.`
@@ -135,10 +160,13 @@ describe(`Test plugin manifest options`, () => {
       theme_color_in_head: false,
       cache_busting_mode: `name`,
     }
-    await onPostBootstrap([], {
-      ...manifestOptions,
-      ...pluginSpecificOptions,
-    })
+    await onPostBootstrap(
+      { reporter },
+      {
+        ...manifestOptions,
+        ...pluginSpecificOptions,
+      }
+    )
     expect(sharp).toHaveBeenCalledTimes(0)
     const content = JSON.parse(fs.writeFileSync.mock.calls[0][1])
     expect(content).toEqual(manifestOptions)
@@ -152,12 +180,15 @@ describe(`Test plugin manifest options`, () => {
       legacy: true,
       cache_busting_mode: `name`,
     }
-    await onPostBootstrap([], {
-      ...manifestOptions,
-      ...pluginSpecificOptions,
-    })
-
-    expect(sharp).toHaveBeenCalledTimes(1)
+    await onPostBootstrap(
+      { reporter },
+      {
+        ...manifestOptions,
+        ...pluginSpecificOptions,
+      }
+    )
+
+    expect(sharp).toHaveBeenCalledTimes(2)
     const content = JSON.parse(fs.writeFileSync.mock.calls[0][1])
     expect(content).toEqual(manifestOptions)
   })
@@ -170,12 +201,15 @@ describe(`Test plugin manifest options`, () => {
       legacy: true,
       cache_busting_mode: `none`,
     }
-    await onPostBootstrap([], {
-      ...manifestOptions,
-      ...pluginSpecificOptions,
-    })
-
-    expect(sharp).toHaveBeenCalledTimes(1)
+    await onPostBootstrap(
+      { reporter },
+      {
+        ...manifestOptions,
+        ...pluginSpecificOptions,
+      }
+    )
+
+    expect(sharp).toHaveBeenCalledTimes(2)
     const content = JSON.parse(fs.writeFileSync.mock.calls[0][1])
     expect(content).toEqual(manifestOptions)
   })
diff --git a/packages/gatsby-plugin-manifest/src/gatsby-node.js b/packages/gatsby-plugin-manifest/src/gatsby-node.js
index f2a845a758080..fa7c3efea1375 100644
--- a/packages/gatsby-plugin-manifest/src/gatsby-node.js
+++ b/packages/gatsby-plugin-manifest/src/gatsby-node.js
@@ -33,13 +33,17 @@ function generateIcons(icons, srcIcon) {
     // Sharp accept density from 1 to 2400
     const density = Math.min(2400, Math.max(1, size))
     return sharp(srcIcon, { density })
-      .resize(size)
+      .resize({
+        width: size,
+        height: size,
+        fit: `contain`,
+        background: { r: 255, g: 255, b: 255, alpha: 0 },
+      })
       .toFile(imgPath)
-      .then(() => {})
   })
 }
 
-exports.onPostBootstrap = async (args, pluginOptions) => {
+exports.onPostBootstrap = async ({ reporter }, pluginOptions) => {
   const { icon, ...manifest } = pluginOptions
 
   // Delete options we won't pass to the manifest.webmanifest.
@@ -74,6 +78,17 @@ exports.onPostBootstrap = async (args, pluginOptions) => {
       throw `icon (${icon}) does not exist as defined in gatsby-config.js. Make sure the file exists relative to the root of the site.`
     }
 
+    let sharpIcon = sharp(icon)
+
+    let metadata = await sharpIcon.metadata()
+
+    if (metadata.width !== metadata.height) {
+      reporter.warn(
+        `The icon(${icon}) you provided to 'gatsby-plugin-manifest' is not square.\n` +
+          `The icons we generate will be square and for the best results we recommend you provide a square icon.\n`
+      )
+    }
+
     //add cache busting
     const cacheMode =
       typeof pluginOptions.cache_busting_mode !== `undefined`